1. Field of the Invention
The invention relates to a method and a device to freely use a mobile terminal, also called handset, when subscribing a new contract with a different operator from the one the mobile terminal is locked with. Such a different operator is for example a Mobile Virtual Network Operator (MVNO), allowing at least voice and data exchanges on a telecommunication network. More particularly, the invention relates to a method and a device for allowing the free usage of mobile terminals.
2. Background Art
Currently, mobile terminals are sold with an operator lock, implemented whereby the mobile operator has subsidized the mobile terminal. The telecommunication operators implement a lock mechanism so that only a subscriber identity module containing the IMSI of that operator can be used. It's known as described in the ETSI standard, that the locked mobile terminal checks for a specific Mobile Country Code (MCC)/Mobile Network Code (MNC) within the International Mobile Subscriber Identity (IMSI) during its initialization phase and unless the IMSI matches the predefined IMSI in the mobile terminal, the subscriber identity module is rejected and considered as not valid by the telecommunication network.
Currently, as disclosed in US2001030235, a procedure for checking the validity of smart cards in a mobile-radio end device is known, comprising the steps of reading, by a mobile-radio end device, a portion of data stored in an International Mobile Subscriber Identity of a smart card in the mobile-radio end device; Comparing the at least a portion of data with allowed value range stored in the mobile-radio end device; and allowing operation of the mobile-radio end device with the smart card by the mobile-radio end device when the portion of data read from the smart card in said step (a) is within the allowed value range stored in the mobile-radio end device.
MVNO today sell many (U)SIM-only packs to end-users. That means that the MVNO provide to end-users an UICC implementing subscriber identity module (SIM) or universal subscriber identity module USIM. When end-users insert their MVNO (U)SIM card into their existing handset, they are often disappointed to find that the handset remains locked to their network facilities unless the end-user pays an unlocking fee or the remainder of the monthly fees until the end of the contract.
The end-user can pay to have their handset unlocked on the black market but this is not always possible and is an extra expense incurred by the end-user.
Currently Different Handset locking mechanisms are implemented and mobile telecommunication operators agree upon several different parameters stored on the subscriber identity module, which must be verified by the handset during the initialization sequence.
These subscriber identity module settings are usually the following fields: Leading MCC/MNC digits of the IMSI field, or GID1/GID2 values. The more important of these two fields is the MCC/MNC digits but both can possibly play an important role for the subscriber identity module initialization check.
A small proportion of Mobile network operators today are implementing SIM lock via GID1/GID2 and the principal means of mobile terminal locking is via the IMSI. Consequently, when a mobile virtual network operators (MVNO) provides a subscriber identity module to a new end-user, unless the end-user has an unlocked mobile terminal, he cannot use the mobile virtual network operators (MVNO) subscriber identity module.
Consequently, when a mobile virtual network operators (MVNO) provides a subscriber identity module to a new end-user, unless the end-user has an unlocked mobile terminal, he cannot use the mobile virtual network operators (MVNO) subscriber identity module.
There is consequently a need to provide a way for the end-user to use his mobile terminal when subscribing for a mobile virtual network operators (MVNO) subscription or prepaid contract.
It is in fact desirable to provide an efficient way to allow the mobile phone end-user to benefit from this new MVNO subscription, even if the mobile terminal he has was previously, during the phase the end-user had a contract with another network operator, locked by the said network operator. There are indeed locked mobile terminals MVNO new customers would like to use.